NEW ALBANY, Ind. — Barack Obama and Hillary Rodham Clinton are undeniably exhausted. They've been campaigning hard for more than a year, and their wall-to-wall schedules won't let up anytime soon. Neither wants to cede ground in their epic struggle for the Democratic nomination.

Fatigue, however, breeds unforced errors _ and both candidates have made some in the past few weeks.

He turned in a weak debate performance in Pennsylvania, took heat for saying residents of small-town America were bitter and inadvertently praised Republican John McCain. She, too, had a sub-par debate and mistakenly claimed to have landed under sniper fire in Bosnia as first lady.

"Sometimes. Yes, of course," Obama, 46, acknowledged Tuesday when asked whether he was exhausted.

The Illinois senator was in the midst of a near 20-hour campaign day. He left his hotel at 6 a.m. for satellite TV interviews in Philadelphia and didn't stop moving until his plane touched down Wednesday in Chicago at 1:30 a.m.

Fourteen years his senior, Clinton laughed off a question about how she maintained a grueling schedule.

"It's been a 15-month campaign and, if everything had been as much fun as Pennsylvania, it wouldn't feel like 15 years," the 60-year-old said _ uncharacteristically showing weariness.

As the Democrats continue their long days of tussling, Republican nominee-in-waiting McCain, energetic at 71, has pared back his schedule considerably from the before-sun-up to after-sun-down days of the GOP primary fight.

Since the Arizona senator wrapped up the nomination last month, he has kept to just one or two public events a day. To be sure, he's at work behind the scenes raising money and preparing for the general election. But most weekends he opts for down time in Phoenix or at his cabin in Sedona, Ariz., resting up for the fall fight.

It's a luxury Obama and Clinton don't have.

The next Democratic primaries _ Indiana and North Carolina _ are May 6, just two weeks away, and the stakes are extraordinary.

So, the excruciatingly long days will continue.

The drawn-out race clearly weighs on Obama; he talks about it at every stop.

"I've been running for president for about 15 months now, which means that there are babies who are now walking and talking, who were born since I announced for president," he said again Wednesday, campaigning in this Ohio River city. "This has been a long primary season."

Obama also frequently mentions how rarely he gets to see his family. He rearranged his schedule so he could return to Chicago late Tuesday to see his daughters off to school Wednesday. He plans no public events today, just down time at home in Chicago.

He took his family to the Virgin Islands last month for a quick rest, but went full-boar in the run up to the Pennsylvania primary. He typically started the day at dawn with an early morning stop at a diner and ended with a nighttime rally. Several other events _ and numerous interviews with local and national media outlets _ were packed in between.

To combat exhaustion, Obama catnaps on his plane. Lithe and athletic, he prioritizes daily exercise to keep up his energy. But there are physical signs of the stress; his hair has grown grayer since he began campaigning.

For her part, Clinton is a veteran of her husband's back-to-back White House races and is keenly aware of the toll it takes on body and spirit. She, too, takes short naps on her plane and eats a steady diet of hot peppers, which she believes has helped her stave off illness. But she says she's getting very little exercise.

The former first lady goes to great pains to manage and hide her fatigue, mindful of Obama's youth and exuberance. Hair and makeup specialists travel with her to help her look fresh from morning until night. When she talks about the long campaign, she tries to be lighthearted and humorous.

However, when pressed about the Bosnia gaffe during last week's debate by a voter named Tom Rooney, Clinton blamed fatigue.

"I will either try to get more sleep, Tom or, you know, have somebody that, you know, is there, as a reminder to me," the New York senator said.

Her schedule is punishing. Clinton usually is up at dawn to prepare for local morning TV and radio interviews, zips to events in far flung cities throughout the day and into the evening, and often doesn't go to bed until after midnight.

In Memphis, Tenn., this month to commemorate the 40th anniversary of the assassination of Martin Luther King Jr., Clinton didn't get to her hotel until 5 a.m. after a redeye flight from California.

She was onstage before television cameras just 6 hours later.

NEW ALBANY, Ind. — Barack Obama and Hillary Rodham Clinton are undeniably exhausted. They've been campaigning hard for more than a year, and their wall-to-wall schedules won't let up anytime soon. Neither wants to cede ground in their epic struggle for the Democratic nomination.

Fatigue, however, breeds unforced errors _ and both candidates have made some in the past few weeks.

He turned in a weak debate performance in Pennsylvania, took heat for saying residents of small-town America were bitter and inadvertently praised Republican John McCain. She, too, had a sub-par debate and mistakenly claimed to have landed under sniper fire in Bosnia as first lady.

"Sometimes. Yes, of course," Obama, 46, acknowledged Tuesday when asked whether he was exhausted.

The Illinois senator was in the midst of a near 20-hour campaign day. He left his hotel at 6 a.m. for satellite TV interviews in Philadelphia and didn't stop moving until his plane touched down Wednesday in Chicago at 1:30 a.m.

Fourteen years his senior, Clinton laughed off a question about how she maintained a grueling schedule.

"It's been a 15-month campaign and, if everything had been as much fun as Pennsylvania, it wouldn't feel like 15 years," the 60-year-old said _ uncharacteristically showing weariness.

As the Democrats continue their long days of tussling, Republican nominee-in-waiting McCain, energetic at 71, has pared back his schedule considerably from the before-sun-up to after-sun-down days of the GOP primary fight.

Since the Arizona senator wrapped up the nomination last month, he has kept to just one or two public events a day. To be sure, he's at work behind the scenes raising money and preparing for the general election. But most weekends he opts for down time in Phoenix or at his cabin in Sedona, Ariz., resting up for the fall fight.

It's a luxury Obama and Clinton don't have.

The next Democratic primaries _ Indiana and North Carolina _ are May 6, just two weeks away, and the stakes are extraordinary.

So, the excruciatingly long days will continue.

The drawn-out race clearly weighs on Obama; he talks about it at every stop.

"I've been running for president for about 15 months now, which means that there are babies who are now walking and talking, who were born since I announced for president," he said again Wednesday, campaigning in this Ohio River city. "This has been a long primary season."

Obama also frequently mentions how rarely he gets to see his family. He rearranged his schedule so he could return to Chicago late Tuesday to see his daughters off to school Wednesday. He plans no public events today, just down time at home in Chicago.

He took his family to the Virgin Islands last month for a quick rest, but went full-boar in the run up to the Pennsylvania primary. He typically started the day at dawn with an early morning stop at a diner and ended with a nighttime rally. Several other events _ and numerous interviews with local and national media outlets _ were packed in between.

To combat exhaustion, Obama catnaps on his plane. Lithe and athletic, he prioritizes daily exercise to keep up his energy. But there are physical signs of the stress; his hair has grown grayer since he began campaigning.

For her part, Clinton is a veteran of her husband's back-to-back White House races and is keenly aware of the toll it takes on body and spirit. She, too, takes short naps on her plane and eats a steady diet of hot peppers, which she believes has helped her stave off illness. But she says she's getting very little exercise.

The former first lady goes to great pains to manage and hide her fatigue, mindful of Obama's youth and exuberance. Hair and makeup specialists travel with her to help her look fresh from morning until night. When she talks about the long campaign, she tries to be lighthearted and humorous.

However, when pressed about the Bosnia gaffe during last week's debate by a voter named Tom Rooney, Clinton blamed fatigue.

"I will either try to get more sleep, Tom or, you know, have somebody that, you know, is there, as a reminder to me," the New York senator said.

Her schedule is punishing. Clinton usually is up at dawn to prepare for local morning TV and radio interviews, zips to events in far flung cities throughout the day and into the evening, and often doesn't go to bed until after midnight.

In Memphis, Tenn., this month to commemorate the 40th anniversary of the assassination of Martin Luther King Jr., Clinton didn't get to her hotel until 5 a.m. after a redeye flight from California.

She was onstage before television cameras just 6 hours later.